In a global-shutter image sensor all of the pixels are exposed simultaneously. This enables the capture of clearer images, notably when capturing moving objects.
A global-shutter sensor conventionally comprises a set of pixels, with each pixel comprising a photosensitive area, a storage area and a readout area. When the sensor is illuminated, electrons are generated and accumulate in the photosensitive area. A control circuit allows the simultaneous passage of the electrons from the photosensitive area to the storage area, then to the readout area. A non-limiting example of such a sensor and of its operation is described in published French patent application FR3000606.
Front-illuminated global-shutter image sensors exist but are difficult to integrate in three-dimensional integrated structures, notably due to the necessity to make the storage area opaque to minimize or reduce noise.